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Which drywall manufacturers are safe?

06-07-2009, 09:50 PM

I want names. We've heard about so-called "chinese drywall", but I never heard actual names of manufacturers that were under suspicion.

Now it looks like the problem may not just be limited to drywall imported from China. I just saw on the news that a family is suing "Atlanta Pacific" for a similar effect,http://money.cnn.com/2009/06/05/pf/s...n=money_latest
I read the article, and it sounds ominous.

So, exactly which US-based drywall manufacturers *do not* use this synthetic gypsum that apparently comes from the scrubbing of coal smokestacks? If it turns out the Atlanta Pacific drywall really is tainted too, then where does it end? www.gypsum.org put out a flyer saying that it's common for its member companies, which includes Atlanta Pacific, to use synthetic gypsum. Is there a "safe source" for drywall that doesn't use synthetic gypsum in their drywall formulation? If there exist domestic manufacturers who don't use synthetic gypsum, I want some names. I'm ready to switch suppliers *now*. I'll be happy if domestic manufacturers prove themselves innocent, but meanwhile I would prefer to avoid any possible problems.

Comment

Drywall is made from gypsum, which is calcium sulphate CaSO4.
The bad drywall, apparently, is contaminated with calcium sulphite CaSO3. Sulphur contained in coal can burn down to SO3 or SO2, depending on the oxygen concentration. SO3 makes sulphates, SO2 makes sulphites.

Wikipedia article about calcium sulphite tells it straight:

Like other metal sulfites, calcium sulfite reacts with acids to produce the respective salt, sulfur dioxide gas and water. For this reason, CaSO3 is not a desirable compound in drywall - when humid, it releases sulfur dioxide as moisture and carbon dioxide are absorbed and mix to form carbonic acids.

"When we build let us think we build forever. Let it not be for present delight nor for present use alone. Let it be such work that our descendants will thank us for, and let us think, as we lay stone upon stone, that a time is to come when these stones will be held sacred because our hands have touched them, and that men will say, as they look upon the labor and wrought substance of them, "See! This our fathers did for us."
John Ruskin (1819 - 1900)